1. Technical Field
The present invention relates to a database search system, and more particularly to a search method for carrying out the retrieval of record and search key between a plurality of databases in a chain-reactive manner.
2. Background Art
There are cases where various records regarding a particular theme are stored in a plurality of different databases. In a typical example, a plurality of databases in which attributes from different viewpoints regarding a particular gene or protein are stored as records are operated by separate organizations. Users of these databases can utilize such a group of databases mainly in the following two ways.    (1) To input a search key concerning a single theme into a plurality of databases in a parallel manner, and then retrieve records.    (2) To input a search key concerning a single theme into one specific database, and refer to resultant, retrieve records. The records in many cases describe link information to related records in the form of search keys that can be entered into other databases. Thus, a user can acquire the search keys and enter them into the databases to which they can be entered, so that the user can refer to a retrieved record.
When there are a plurality of databases, the form of the search keys that can be entered into the databases, namely record IDs or document Nos., are often different. Accordingly, in mode (1) of use, the user must obtain different kinds of search keys corresponding to a desired theme in advance, thereby complicating the operation. Thus, it is more advantageous to employ mode (2) of use, wherein the entry of a single search key corresponding to a desired theme enables the retrieval of records concerning the same theme in other databases in a chain-reactive manner.
Further, a method is used whereby the process of retrieving extracting a search key and entering it into another database is carried out for three or more databases, instead of two databases on a one-to-one basis, in a chain-reactive manner, and the process is automatically repeated until reaching a terminal database designated in advance by the user. In accordance with this method, a chain-reactive trace of the keys that are information linking to related records enables indirect entry of a search key that cannot be directly entered into the desired terminal database, and therefore records in the terminal database can be retrieved and referred to, so that the efficiency of the search-key input operations can be significantly improved.
The Japanese patent application kokai 2000-222418, laid open 11th August, 2000, which discloses a data base retrieving device, mode (2) of the device is provided with two or more data bases, a retrieving object data base input device for specifying a data base to be retrieved, a priority information input device for setting up priority at the time of retrieving each specified data base to be retrieved, and a retrieving request input device for inputting information indicating a retrieving request. The device is also provided with a data base retrieving device for applying retrieval corresponding to priority to the data base to be retrieved and extracting information having high relationship with the inputted retrieving request, a modedata base restricting device for restricting a data base to be used for retrieval and a data display device for displaying extracted information.
The above described database enables to execute retrieval considering the priority of respective databases in the case of retrieving plural databases and to display and report a list of retrieved results to a user so that the features of retrieved results can easily be understood.
The mode (2) of use, however, has the following problems. Namely, whether or not a key as information linking to related records of other related databases is contained in records of each database depends on the intention of the record producer of each database, and those intentions are largely dependent on the personal viewpoint of the producer. Although it is fundamentally preferable to enable chain-reactive processing until records are retrieved from the terminal database as related records, a suitable record often cannot be retrieved from the terminal database if any one database on the path (hereafter referred to as “intervening database”) does not contain a search key. There is no solution for the above problem in the Japanese patent application.